Garry's Mod 13(ver. 14.01.22) won't let me connect to my cousin's account.

For the past few weeks. I’ve been trying to connect to my cousin, Andrew’s, Gmod server. It keeps “failing after 4 retires”.
Andrew and connect with his other friends, but not me. I’m even using Hamachi to connect and it’s not working.
What do I do? I looked up how to fix it and none of the threads I’ve come across are helping.
It really doesn’t help that they’re all almost out-dated(Like, Gmod 10 or 12)
This is pissing me off…

The current version of Gmod I have is 14.01.22.
What do I do?

This is in the wrong section, anyways, can you connect to other servers? make sure you firewall is not blocking anything

Yes, I can connect to other servers. I can’t connect to my cousin’s though. We even tried the Firewall thing.

Nevermind ,I got it working. Had to reinstall Hamachi… I’m stupid.